The pertinent prior art form of flow restriction is the segmental wedge, and the pertinent prior art form of flow measuring assembly is one that is effectively integral with the pipe or other conductor of flow material.
The prior art of the segmental wedge is relatively compendiously set forth in ISA REPRINT N.F. 77-820, which is a paper by Raymond E. Owen, entitled SEGMENTAL WEDGE FLOW ELEMENT, and reproduced as Paper 820, pages 51-58 of ADVANCES IN INSTRUMENTATION, vol. 32, Part 4; Proceedings of the ISA Conference Exhibit, Niagara Falls, Oct. 17-20, 1977, Instrument Society of America, 400 Stanwix Street, Pittsburgh, Pa. 15222.
The prior art integral orifice assembly is generally a two part body having a pair of coaxial bores separated by an orifice plate and sealing gaskets sandwiched between the two body parts. The body parts are in effect inserted in a gap in a pipe line the flow through which is to be measured, with the two bores effectively forming parts of the bore of the pipe. The body parts are aligned in a jig, clamped together with the orifice plate and gaskets positioned therebetween to form the flow metering assembly, and the fluid pressure transmitter or other fluid pressure receiving means clamped to such assembly, i.e., to the clamped body parts.
With the present invention, not only do we provide the advantages of using the wedge as a flow metering restriction, and of having an integral assembly, but we also eliminate the previously mentioned orifice sealing gaskets and jig, and as well, obviate all the problems of alignment which are entitled by the prior art composite of orifice, sealing gaskets and two body parts. While at first sight such advantages may not seem substantial, nevertheless the prior art and new structures (the integral orifice assembly, alignment jig and our integral wedge assembly) are massive, rather expensive, precisely-machined metal castings, each casting about as much as either of the others, so elimination of the jig, and as well the skilled labor costs which its use requires, provides substantial savings. Inasmuch as the wedge is also functionally equal to or better than the conventional orifice, venturi, or nozzle, our integral wedge flow metering assembly represents an unusually advantageous advance in the art of flowmetering.